/**
 * $RCSfile$
 * $Revision$
 * $Date$
 *
 * Copyright 2003-2007 Jive Software.
 *
 * All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.jivesoftware.smackx;

import org.jivesoftware.smack.ConnectionCreationListener;
import org.jivesoftware.smack.Connection;
import org.jivesoftware.smack.XMPPException;
import org.jivesoftware.smack.packet.Message;
import org.jivesoftware.smackx.packet.DiscoverInfo;
import org.jivesoftware.smackx.packet.XHTMLExtension;

import java.util.Iterator;

/**
 * Manages XHTML formatted texts within messages. A XHTMLManager provides a high
 * level access to get and set XHTML bodies to messages, enable and disable
 * XHTML support and check if remote XMPP clients support XHTML.
 * 
 * @author Gaston Dombiak
 */
public class XHTMLManager {

	private final static String namespace = "http://jabber.org/protocol/xhtml-im";

	// Enable the XHTML support on every established connection
	// The ServiceDiscoveryManager class should have been already initialized
	static {
		Connection
				.addConnectionCreationListener(new ConnectionCreationListener() {
					public void connectionCreated(Connection connection) {
						XHTMLManager.setServiceEnabled(connection, true);
					}
				});
	}

	/**
	 * Returns an Iterator for the XHTML bodies in the message. Returns null if
	 * the message does not contain an XHTML extension.
	 * 
	 * @param message
	 *            an XHTML message
	 * @return an Iterator for the bodies in the message or null if none.
	 */
	public static Iterator getBodies(Message message) {
		XHTMLExtension xhtmlExtension = (XHTMLExtension) message.getExtension(
				"html", namespace);
		if (xhtmlExtension != null)
			return xhtmlExtension.getBodies();
		else
			return null;
	}

	/**
	 * Adds an XHTML body to the message.
	 * 
	 * @param message
	 *            the message that will receive the XHTML body
	 * @param body
	 *            the string to add as an XHTML body to the message
	 */
	public static void addBody(Message message, String body) {
		XHTMLExtension xhtmlExtension = (XHTMLExtension) message.getExtension(
				"html", namespace);
		if (xhtmlExtension == null) {
			// Create an XHTMLExtension and add it to the message
			xhtmlExtension = new XHTMLExtension();
			message.addExtension(xhtmlExtension);
		}
		// Add the required bodies to the message
		xhtmlExtension.addBody(body);
	}

	/**
	 * Returns true if the message contains an XHTML extension.
	 * 
	 * @param message
	 *            the message to check if contains an XHTML extentsion or not
	 * @return a boolean indicating whether the message is an XHTML message
	 */
	public static boolean isXHTMLMessage(Message message) {
		return message.getExtension("html", namespace) != null;
	}

	/**
	 * Enables or disables the XHTML support on a given connection.
	 * <p>
	 * 
	 * Before starting to send XHTML messages to a user, check that the user can
	 * handle XHTML messages. Enable the XHTML support to indicate that this
	 * client handles XHTML messages.
	 * 
	 * @param connection
	 *            the connection where the service will be enabled or disabled
	 * @param enabled
	 *            indicates if the service will be enabled or disabled
	 */
	public synchronized static void setServiceEnabled(Connection connection,
			boolean enabled) {
		if (isServiceEnabled(connection) == enabled)
			return;

		if (enabled) {
			ServiceDiscoveryManager.getInstanceFor(connection).addFeature(
					namespace);
		} else {
			ServiceDiscoveryManager.getInstanceFor(connection).removeFeature(
					namespace);
		}
	}

	/**
	 * Returns true if the XHTML support is enabled for the given connection.
	 * 
	 * @param connection
	 *            the connection to look for XHTML support
	 * @return a boolean indicating if the XHTML support is enabled for the
	 *         given connection
	 */
	public static boolean isServiceEnabled(Connection connection) {
		return ServiceDiscoveryManager.getInstanceFor(connection)
				.includesFeature(namespace);
	}

	/**
	 * Returns true if the specified user handles XHTML messages.
	 * 
	 * @param connection
	 *            the connection to use to perform the service discovery
	 * @param userID
	 *            the user to check. A fully qualified xmpp ID, e.g.
	 *            jdoe@example.com
	 * @return a boolean indicating whether the specified user handles XHTML
	 *         messages
	 */
	public static boolean isServiceEnabled(Connection connection, String userID) {
		try {
			DiscoverInfo result = ServiceDiscoveryManager.getInstanceFor(
					connection).discoverInfo(userID);
			return result.containsFeature(namespace);
		} catch (XMPPException e) {
			e.printStackTrace();
			return false;
		}
	}
}
